Abortion is such a controversial topic. By funding it in other countries, it automatically places the whole country of the US in the "pro-choice" category. That can have some ramifications in terms of voter approval for the current president. Abortion can be costly, but it is a choice to have an abortion, therefore the US should not have to pay for other people choosing to get one.
I am about freedom of choice, but our government shouldn't be paying for it. Nor should the government be trying to tell people it is right or wrong. Funding them would be like taking a stance for it. If we wanted to help support an open and increase in availability of healthcare in general that would be a good thing, and if in the process abortions became available that would be ok. If a person needs and wants an abortion making it available is one thing, but paying for it is another.
This topic that our government hypocritically allows in this country shouldn't be allowed at all. We are "One Nation Under God" and since we allow both same-sex marriage, abortion, etc., we are hypocrites. So why should we fund this in other countries? Answer is: we shouldn't. It's horrible to even really think that.
I believe the US should not fund abortions in other countries for the fact the government is already in debt. It wouldn't make sense to have funding in other countries when the money can be put to better use at home. Second, the US is already having debates in congress over abortion now.
Why fund in another country something that you can't decide if you believe it is moral or not? Then the citizens tax dollars will be going right out the country, and can cause more protest and debates. There may be more reasons, but those are the main reason that stick out to me that don't seem right.